I. Field of the Invention:
The present invention pertains to a device for processing large volumes of organic waste material from chemical or refinery processes, remediation projects in either a batch or continuous mode. The device is an integrated unit which can be transported from site to site to process or recycle waste materials from various types of chemical manufacture, refinery and processing operations into an essentially homogeneous, substitute fuel on a location at or near the source of the generation or storage of such waste materials thereby eliminating the necessity of transporting large volumes of untreated waste materials to remote, fixed treatment and processing facilities.
II. Description of the Relevant Technology:
In various chemical, refinery and manufacturing processes or environmental remediation projects, a variety of hazardous and non-hazardous waste materials are generated which may require post-generation treatment, separation, or other processing to facilitate waste minimization, disposal, removal, useful product recapture, or recycling. One impediment to the management of such waste materials is the general non-homogeneous, solid or sludge-like nature of such materials. The wastes generally exist as an agglomeration of various solids, liquids, semi-solid and sludge-like components. Depending on composition and chemical make-up, some of the compounds in the waste may be separable and useable in other applications or other processes if they can be recovered. Typically, the wastes are not amenable for reclaiming such useable compounds and are processed to produce materials suitable as substitute fuels for certain kilns, industrial furnaces, boilers and the like which have regulatory approvals to burn such substitute fuels.
In the past such high-volume waste materials were treated and/or stored in drums, tanks, lagoons or the like indefinitely. The large volume and solid, sludge-like nature of the materials precluded transfer to remote facilities for treatment at such remote treatment facilities employing various separation, processing, recycling, reclamation and/or disposal techniques. This practice of indefinite storage has been eliminated presenting the opportunity and necessity to reclaim, recycle, or process these materials at such storage sites and as they are generated at a facility or site.
Even if physical removal was heretofore possible, transport costs for transferring these waste materials to remote processing facilities made this option cost-prohibitive in many high-volume installations. Subsequent Federal regulations made some of these wastes subject to hazardous waste regulation and land disposal restrictions. Thus the need for treating, processing, or removing large volumes of such materials in an environmentally safe manner was greatly increased.
This problem is particularly pronounced with hazardous by-product materials such as the still bottoms and API separator sludges from various petroleum refinery and distillation processes. Also, lagoon cleanup as part of environmental remediation projects produce large volumes of sludge material. These materials, in general, are non-homogeneous sludge-like materials which contain high concentrations of organic compounds, solids and can be extremely dense and/or viscous making them difficult to handle, pump, and transport.
A variety of partial remedies to the shipping and handling problem have been proposed. U.S. Pat. No. 4,082,672 to Petroski discloses a trailer specifically designed for receiving, transporting, and unloading sludges which range in consistency from liquid to semi-solid. The reference fails to provide or suggest any procedure or apparatus for reducing the volume of sludge to be transported for processing or a method for processing the material into useful forms or otherwise recycling the component materials. U.S. Pat. No. 4,377,478 to Wiedeman discloses a mobile apparatus for syphoning and dewatering sludge. While the sludge volume is reduced, the reference fails to disclose any method or apparatus for processing or recycling the dewatered sludge into a useful product.
A variety of waste water treatment methods and apparatuses have been disclosed. U.S. Pat. No. 4,536,286 to Nugent discloses an apparatus which can process the contents of the storage lagoons containing water and up to 15% solids processed by the Nugent apparatus which removes the solids present in the waste stream and reduces this stream by dewatering by up to 75% of the original volume. This operation is performed by a transportable waste treatment apparatus composed of a pair of mixing tanks in which the waste stream is negatively charged and admixed with a suitable flocculent. The Nugent device also includes a settling tank equipped with a plurality of baffles as well as multiple sludge drain-off means. Once appropriate settlement and separation has occurred, the Nugent device anticipates that the separated water can be discharged directly into a suitable effluent stream while the collected concentrated solids are removed for appropriate disposal. U.S. Pat. No. 4,383,920 to Muller et al discloses a self-contained mobile system for purifying aqueous liquids which involves the sequential contact of the liquid with various ion exchange media contained in separate reaction vessels which are housed in a reclaiming or recycling the resulting sludge. Furthermore, neither reference is effective in treating non-aqueous materials.
U.S. Pat. No. 3,630,365 to Woodbridge discloses a mobile liquid waste treatment system adapted to be positioned on a series of rail cars and brought to the contaminated site. The Woodbridge apparatus includes a mixing vessel, a series of biochemical reaction tanks, a centrifuge, filter unit with means for removing separated solids and an irradiation unit for exposing the treated liquid to predetermined doses of gamma radiation. This system is specifically designed to augment existing waste water treatment facilities.
A trailer-mounted apparatus designed specifically for decontaminating PCB-containing hydrocarbons is proposed in U.S. Pat. No. 4,514,294 to Layman et al. The device includes reaction vessels capable of receiving de-watered hydrocarbons and raising the hydrocarbon temperature to about 130.degree. C. and directing the material through an injector into a stoichiometric quantity of sodium. The device is equipped with appropriate heat exchangers as well as suitable heating units, PCB monitoring units, and recirculating devices to re-inject the hydrocarbon stream until the PCB level is lowered by the desired amount. The apparatus also includes suitable sodium separators as well as hydrocarbon filters. This device is specifically designed for the chemical destruction of PCB and fails to provide a recycling method for still bottoms and the like.
Thus, despite a great deal of activity in producing mobile water purification devices and site-specific chemical purification devices, no mobile or skid-mounted device has been proposed which can be employed to handle and process materials such as solids, semi-solids, or pumpable sludges on site. Moreover no device has been developed which will process such material in a manner which recylces such hazardous and non-hazardous organic material into suitable substitute fuel materials.
It is desirable to provide an apparatus and method for permitting effective processing of recyclable components of a waste stream for formulation into a useful substitute fuel product or to make the wastes more amenable for movement or removal to an incineration facility for thermal destruction of the materials. It is also desirable that the apparatus employed be mobile and/or skid-mounted and readily transportable to the waste generation or storage site.